Blowing device for rock drills



June 1932- E. B. LEAR BLOWING DEVICE FOR ROCK DRILLS Filed July 16, 1931 INVENTOR.

Ea ZB'Leafl. w;

Hi5 ATTORNEY,

I a "one object Patented June 7, 1932 PATENT, OFFICE BQLEABQoE r ILLI Psnn RG, NnwJERsEY, ASSIGNOR 'ro INGERSOLL-RAND coM- mm OFVJERSEYI-CITY, NEW annsny; A coaPoRATIoN or NEW mnsny 3 invention relates; to percussive tools, -buU InoreiparticuIarIyto a blowmg device aor fluid actuatedpercussive tools of theham- 1w." plate type arranged in avalve chamber U for =WhICl1= a plate V disposed in the extension R "inertype'. "'3

of the invention is to selective- 1y admit pressure fiuidunderf-ull'i 1ine -pres- "'sui'e'to the"drill steer rmcleansing the drill hole and another obj e ct istom'ai'ntain thedisiti'ibuting valveand' the hammer piston of the 10 'drill"stationary jduiing--=the blowing-'- operaxiiiin; M17, '1

n 5. I- Q objects'will be in part obvious and inpart "poiht'ed 'foiithereinaftlerfi" I In heQ'accompanyingdrawing in 'which- 16 similar referencech'aracters refertosimilar Fi "re-Tie a'sectionalelevation of a'percussive tool jliavir' g {the invention applied q thereto and showing the position of theparts i di1r'ing th'e' blowihg operation; and;

the position-of the valve holding device durin .the normal operation of the drillfi j H eferring "more particularly to the"drawing, designates generall a permissive tool offthe hammer type comprising a cylinder '13 having a p-i ston chamber C therein to accommodate a reciprocatory' hammer pis- 'Thepiston 1) may 'be'ot a well known type having a h'ead'E slidable in the piston chamber and controlling a free exhaust port F in the cylinder B. Onthe front end of the pisto'n D is an integraljstem or extension G having a series of flutes H to interlock with ribs J carried by a chuck K which is encased by v a front head L. 4

The chuck Kmay rotate freely within the front head L and is adapted to receive the shank end of a working impleme'nt O, as for v instance a drill steel, which may be suitably "interlocked withthe chuck in a well knownmanner to rotate therewith. A front cylinway into each and has a-bore Q, to serve as a guide for the extension G of the piston.

Seated on the rear end of the cylinder B is an extension R having: an end wall S at its forward or inner end to serve as a closure for generally by Y der washer P interposed between the cylinder B and the front head L may extend part mama evice son soc-K nnILLs Ap plic ation file d m 16,6931. Serial No. 551,149.

the rearward end of the piston chamber C.

FThe-rear end of the wall 8' acts as a seatfor a distributing valve Tfof the oscillatory serves asfa rearward closure. The valve T is of a wellknown'type adapted to oscillate or rock from onelimiting position to another to control the distribution of pressure fluid from the valve chamber Uto the ends ofthe piston chamber Ci The admission of such pressure fluid into the rear end of the piston chamber for actuating the'piston Disconveyed thereto by a rear inlet passage Win the wall S, and a front inlet passage Xv formed inthe wall S and the cylinder B serves to convey pressure fluid from the valve bhamber U to the front end of the piston chamber C. v v

tool may be provided with-rotation mechanism of a well-knowntype'designated and comprising, i as illustrated a rifle bar Z which may extend into and'interlock ingly engage-the piston D in the usual manner. A ratchet ring I) seated on the rear end of the plate V encircles a head 0 carried by the rifle bar Z to act as an abutment for spring pressed pawls (1 carried by the head. The ratchet ring bmoreover, acts as a seat for a back head e which serves as a closure for the rear end of the tool to which it may be secured, as may also be the extension R, by means of the usual spring pressed side bolts (not shown).

The back head a is shown provided with a throttle valve f to control communication between a source of pressure fluid supply and a passage 9 in the back head 6 and which passage opens into a supply reservoir h also in the back head. Communication between the supply reservoir h and the valve chamber U is aiiorded by supply passages j in the ratchet ring I) and the plate V.

In accordance with the practice of the invention means are provided for assuring an uninterrupted supply of pressure fluid to the drill hole whenever the detritus tends to accumulate therein and which, if not expelled from the drill hole, will form a collar adjacent the cutting bit and seriously impede the action of the rotation mechanism. T that for one eiidi (if; a'isp'ring grwliichen'circles'the plunger 0 and seats with its opposite end against the extension R. i l-he plunger (may be retainedin the bor'k in any siiitable as for instance} bymeans of a pin 1" disposed in the extension R and extending through anelongatd"slot"s in the surface of the plunger o. ,The inner end t of the plunger may extend into the Valve chamber Il a/11d on.the lower.=side-of .the eplunger; (ii-adjacent; the-end. t is an inclined surfalce-ru which iwhenlthczplunger. o. is actu- {ated -inthe {direction oi .the valve chamber, soiwilli engage thefreartsurtaceiof the valve and 3 presszthe. 'endof;.the walwe tightly @upon :its QSBHt-BEO. close.thez-reaninletqpassageW. 'In order to. assure. asuit'able pressureiin the hlfifl l emLof:tlieipistonrchamberic 80 :that the .125 ,pressure;acting sagainstqthe. front end of the headzE of?theipis,toniwill be 'unableto actuate the piston (into; a; (position 'to place the :front .end1bfi'the piston chamben :C. in communica- :tien withthe atmosphere {through .the free'exasolha-ustpport F, ithesplunger 0=is provided with ;-a passage uiwhich, when ;the plungemis-depressed; to; lock Pthe -.val-.ve iinvposition', will be nin ccmmun-ication with the-*valvechamber .U and also with a passage w in the extension-R .-.s5;;andzwl1ich*latter;passage o ens into the-rear 2-,end-oflthe pistomchamber;

.llheroperationwoflthe: device is as follows lVith ithe throttle vailvefi in the open position pnessurefiuidriwi-l-l flow into :the :valve' chamaeo bertU-iwhe re;it;:will be normally distributed abythe-valve" 'E and flow'to the rear and front -.-ends of thef-piston lchamber Clthrough theainl-let-passages W and K respectively. The pis- .to n .'Dnwill them reciprocate to. deliver. its 5; blows against .the' working implement. O and during its reciprocations will: place. -.the:-.ends I of :thepiston chamber alternately :incommuv nication with the atmospherethrough the exhaust port F forexhausting the fluid utilized .1 for; actuating :the piston.

. I Duringithis operationof the tool a-portion i ofipressure fluid will flow ithrough the'flutes 1-1, thence through the-drill .steel 0 into the idrillrhole 5 during each; admission of pressure its fluid-to the front endlofthe piston chamber C to remove the cuttings from the-drill hole.

-As itheide'pth. of v the drill hole. increases, it becomes increasingly. difficult :to completely iremoweall the cuttings'so that, in consequence eer-the. cuttings Willi-accumulate therein and -bringiabout the; unfavorable condition here- .dnbefore. referred. to.

"Vltheneverzit becomes; apparent that thealternate. puffs :ofpressure fluid issuing from ES the. ifironti'endiofthe pisto'n'cha-mber C areinadequate to maintain the drill hole free from cuttings the plunger 0 may be depressed to the position illustrated in Figure 1. In this position the inclined surface a will engage the rear end of the valve and hold the valve tightly seated over thevrear inlet passage W. I The opposite-end of the valvefiwillithen be fullyraised and pressure fluid will flow from the valve chamber U through the front inlet pass'age and through the cfront end of the pistoirchamber "G, thence threuglr the flutes Hand through the drill steel 0 into the drill hole'to "blowthe-cuttings therefrom. In the ,.lo cki,ng positionpf the plunger 0 the passage 0 will be in'cominunication with the valve chamber U. and. also with the, passage w. Pressure 2 fluid will therefore. beadmitted ,in .restricted. quantity as. com Jaredwith .that flowing through the passage into .therear .end-ofthe piston chamher C to maintain an .-.suitablez pressure. therein to. balance ':that acting against. the. forward, pressure area jor a -Qfeep D-. 1 V In tools; wherein .theppiston lis provided throughout length vwith a.bQ sucli a i p required to accommodatethe rifle bar a'ri deas a illustrated, alsoa-water gtubearwhicheaitends into the working, implement, pressure suit- "ably balancing-that. .in-.the. trbntendimay be maintainedinthe rear .end .ofthe pistonehamher since, whenever the pressure rarwaifdly of rthe'r piston predominates slightly. .oiierithat .in' the frontend. otnthev piston chamber,..the 1. pressurezfluid will-leak through the. piston" to the drill isteel. .Thepressurein the rearendy --.of--.thevpiston chambenwill thus be lowered to the same value as that existingin ithe'flfront end.

.flhe blowing, device. is, however, applicable nforuusein connection with tools..employing. -solid pistons. When so-used .the..excess-. of pressurewhich may. accumulate in the. rear ..end of the piston chamber will-merely...de-

press the piston D sufliciently to slightly open the exhaust port F, whereupon isuchuexcessvpressure. fluid will escape and .thepiston .1) may then immediately return to close the .exhaust portF. In .tools, -.however, suclras that illustrated wherein pressure-fluid may p'ass'through'the-piston it has been found that? the pressure fluida'cting against the-opposing end areas of the piston will be balanced I and that the piston willfltherefore remain immovable during the blowing operation.

- After the- @drill ho-lehasbeen prpperly cleansed the plunger 0' maybe-released: and .'the springs .g maymove it out-of-thelpath of the valveiT and=will-hold it thereduring the subsequentnoimal operationofthe drill.

I claim:

1. A fluid actuated rockdrill-comprising a. casing having a piston chamber and anexhaust port, a hammer piston inthe piston .ichamber controlling the-exhaust port. and i having a. blower passage,- an automatic valve" i 3- 2. A fluid actuated rock drill comprising for distributing pressure fluid to the piston chamber, and means for holding the valve in position to supply pressure fluid to only one end of the piston chamber and to the blower passage and having a passage admitting pressure fluidto the other end of the piston chamber to prevent the piston from communicating the first said end of the piston chamber with the exhaust port.

a casing having a piston chamber and an exhaust port, a hammer piston in the piston chamber controlling the exhaust 1 port and having a blower passage, an automatic valve for distributing pressure fluid to the piston chamber, and means for holding the valve in position to supply an unrestricted volume of pressure fluid to only one end of the piston chamber and the blower passage and said means admitting a restricted supply of pressure fluid into the other end of the piston chamber to maintain the piston in position to cover the exhaust port.

3. A fluid actuated rock drill comprising a casing having a piston chamber and an exhaust port, a hammer piston in the piston chamber controlling the exhaust port and vhaving a blower passage, a valve chamber having an automatic valve therein to distribute pressure fluid to the piston chamber, a plunger for holding the valve in position for V supplying pressure fluid to oneend of the piston chamber and to the blower passage, and restricted passages in the plunger and the casing to convey pressure fluid from the valve chamber into the other end of the piston chamber to prevent the piston from communicating the first said end of the piston chamber with the exhaust port.

9 4;. A fluid actuated rock drill comprising a casing having a piston chamber and an exhaust port, a hammer piston in the piston chamber controlling the exhaust port and having a blower passage, a valve chamber 5 having an automatic valve therein to distribute pressure fluid to the piston chamber, a plunger for holding the valve in position for supplying pressure fluid to the front end of to act upon the valve for cutting off communication between the rear end of the piston chamber and the valve chamber and to admit pressure fluid from the valve chamber into the front end of the piston chamber and to the blower passage, a passage in the casing opening into the rear end of the piston chamber, and a passage in the plunger adapted to register with the passage in the casing for admitting pressure fluid into the rear end of 1 the piston chamber during the blowing operation to maintain the piston in an intermediate position in the piston chamber for closing the exhaust port.

In testimony whereof I have signed this specification.

EARL B. LEAR.

the piston chamber and to the blower pas- V 0 sage, and passages in the plunger and the casing to bleed pressure fluid from the valve chamber into the rear end of the piston chamber to resist the force of the pressure fluid acting against the front end of the piston 5 and thus maintain the piston in an interme diate position in the piston chamber to cover the exhaust port.

5. A fluid actuated rock drill comprising a casing having a piston chamber and an ex- 0 haust port, a hammer piston in the piston chamber controlling the exhaust port and having a blower passage, a valve chamber having an oscillatory plate valve therein to distribute pressure fluid to the piston chamd I ber, a. spring pressed plunger in the casing 

